Bernard of Clairvaux, the twelfth-century monk who wrote that "Jesus is honey in the mouth, melody in the ear, a cry of joy in the heart," was both a mystic and a reformer. His writings reveal a mystical theology that Thomas Merton, a monastic heir to Bernard's Cistercian reform, says "explains what it means to be united to God in Christ but (also) shows the meaning of the whole economy of our redemption in Christ." Critical of the monastic opulence...